Valve mechanism for compound engines.



lmueutoz PATBNTED NOV.,27. 1906.

E. J. ARMSTRONG. VALVE MECHANISM FOR COMPOUND ENGINES.

APPLICATION FILED AUG. 18, 1904. RENEWED APR. 17, 1906.

a Hornet;

UNITED STATES PATENT OFFICE.

VALVE MECHANISM FOR COMPOUND ENGINES.

Specification of Letters Patent.

Patented Nov. 27,1906.

Application'filad August 18, 1904. Renewed April '17, 1906. Serial No. 312,141.

T0 to whom it may concern.-

Be it known that I, EDWIN J. ARMSTRONG, a citizen of the United States, residing at Erie, inthe county of Erie and State of Pennsylvania, have invented certain new and useful Improvements in Valve Mechanism for Compound Engines; and I do declare the following to be a full, clear, and exact description of the invention, such as willenable others skilled in the art to which it appertains to make a and use the same.

This invention relates-to the valve mechanism of compound engines of that type in which the admission of steam to one or more of the cylinders is controlled by varying .the travel of some or all parts of the valve-gearmg.

The object of the invention is to provide means whereby steam may be by-passed from the high-pressure steam-chest to the low-pressure steam-chest and whereby the governor of the engine may control such bypassingmechanism to the-end that the steampressure in the low-pressure steam-chest may be automatically raised when desirable and the maximum power of the engine thereby increased,thus enabling a smaller engine to carry the required overloads and permitting smaller loads to be carried at later cutoffs. This in the case of non-condensing engines is very desirable, as the most econom ical load for such engines is at or near their maximum capacity, while the average loads are ordinarily much less. Hence by increasing the maximum capacity in the manner stated the average load may be carried with greater economy.

A further object of the invention is to provide means whereby the by-passing device may be made an attachment for, rather than an integral part of, the engine, so that in the manufacture of such engines the device may at any time be put on or left ofi, as the operating conditions may make desirable.

It is also an object of the invention to provide means whereby the point in the range of travel of the valve-gearing at which the bypass begins to open may be adjusted to meet the conditions of diiferent installations.

The invention consists in the parts and combinations of parts hereinafter described and claimed.

In the accompanying drawings, forming a part of this specification, Figure 1 is a side elevation of an engine with the by-passing device applied thereto; Fig. 2, a vertical longitudinal section of'oneform of valve adapted for use in my by-passing device, and Fig. 3 a similar View of a different form-of valve which is equally well adapted for such use.

Similar letters refer to similar-partsthroughout all the views.

Referring to the .drawings, A represents the highpressure cylinder, B the low-pressure cylinder, C the piston-rod, D the eccentrio-rod, E the fiy-wheel,-and Fia governor mounted on said wheel, ofa com ound steamengine, all of which maybe of t e usual or of any suitable construction and arrangement.

In carrying out my invention I provide .a valve which is attached to the engine and connected at one side by suitable pipes with the high-pressure steam-chest and at the other side to the receiver of the low-pressure cylinder, the stem of said valve being connected to the governor, so as to .beioperated thereby.

In Fig. 2 I show one form of val-veadapted to carry-out my invention, in whicharepresents a valve casing or body having the threaded openings 6 b at opposite sides and the seat 0 for the piston-valve (if, having a stem 6.

As shown in Fig. 1, the valve is attached in any desired manner to the engine, and one side thereof is connected by a pipe f to the high-pressure-cylinder steam-chest and the other side by a pipe g to the receiver of engine, which receiver is in communication with the steam-chest of the low-pressure cylinder.

The valve d has a considerable lap and is adapted to open at either end of the idle movement provided for by the lap.

A jointed link it connects the valve-stem e to the rock-arm t of the engine, which is reciprocated by the governor F through a movement varying with the load which the engine is carrying, thereby giving a movement of the same character to the by-pass valve d. When the load is increased to a point where the valve travel is approaching the maximum, the by-pass valve (1 will be opened at either end of its movement and will admit steam from the high-pressure-cylinder steam-chest to the low-pressure-cylinder steam-chest, thus enabling a much larger load to be carried by the engine than could otherwise be done. It is desirable that the device be capable of adjustment whereby the point in the range of travel of the valvegear at which the by-pass valve begins to 0 en can be changed to suit conditions. '1 's may be accomplished in several ways, and in Fig. 1 I have shown the rock-arm formed with holes 3', whereby the link it may be attached thereto at difierentradii from the rocker-arm pivot. Also I provide sto valves 7c for the pipes f and g, whereby t e byass valve may be cut ofi from the high and low pressure cylinders when desired.

In Fig. 3 I show another form of valve a puppetvalve-to the stem of which a lever m is connected, which connects with the valve motion. This arrangement allows of considerable movement of the lever without opening the valve; but further movement in either direction will cause it to open, and thus permits the steam from the high-pressurecylinder steam-chest to flow to the lower-pressure cylinder similar to the form of valve first described.

The lever m is formed with the holes n in order to provide for a change in position of attachment of said lever to the link 0, which connects with the valve motion.

Having thus described'my invention, what I claim as new, and desire to secure by Let ters Patent, is

1. In an engine having high and low pressure cylinders and a governor operating to give a variable travel to the valve-gear, a bypass valve connecting the high and low pressure steam-chests and ada ted to be opened by a longtravel of the sai valve-gear.

2. In an engine having high and low pressure cylinders and a governor operating to give a variable travel to the valvegear, an

auxiliary bypass valve connecting the high and low pressure steamchests, and ada ted to be opened only by a long travel 0 the valve-gear.

3. In an engine comprising high and low pressure cylinders, a governor operating to give a variable travel to the valve-gear, a bypass valve connecting the high and low pressure steam-chests and adapted to be opened by a long travel of the valve-gear, and means whereby the point in the range of travel of the valve-gear at which the by-pass valve opens may be adjusted to suit varying conditions.

4. An engine comprising high and low pressure cylinders, a governor operating" to give a variable travel to the valve-gear, an auxiliary by-pass valve connected to said valve-gear and adapted to be opened by a long travel of said valve-gear, said byass valve having communication with the'l igh and low pressure steam-chests, and stopvalves for cutting oif said communication.

In testimony whereof I affix my signature in presence of two witnesses.

EDWIN J ARMSTRONG.

Witnesses:

ROBERT L. KERR, W. W. WELLS. 

